Arthrodopods Flashcards
WHat phlum are athropods and nematodes part of?
Ecdysozoans
What are features of Ecdysozoans?
undergo prosses of ecdysis (or molting)
secrete a protein or polysaccharide rich cuticle that covers their bodies
cuticles are periodically molted
WHat are Nematoda?
roundworms
parasitic, aquatic and terrestrial
Pseudocoelomates with fluid-filled hydrostatic skeletion
long, cylindrical and tapered
collagen cuticle
longitudinal fibres for muscles
WHat is the diversity of Nematodes?
30,000 sopecies described over 1 million estimated
estimates are that there are 57 billion of them for every single living human
WHere do Nematodes live?
soil (anywhere)
abundance positively correlated with organic material soil
Due to presence of nematodes in soil food webs what are they indicators of?
soil health
WHat are the 5 subphylums of Arthropods (one extinct)?
Trilobitomorpha (extinct)
Chelicerata
Myriapoda
Crustacae
Hexapoda
What are arthropod characteristics?
jointed appendages
segmented body
external skeleton
What is the arthropod exoskeleton?
epidermis secretes the exoskeltion or cuticle, is periodically molted
What are the advantages of having an exoskeleton?
provides support and levers for muscle attachment
offers physical protection
serves as a barrier to prevent desiccation
serves as a barrier to prevent infection
WHat are Jointed appendages?
exoskeleton divides into plates and cylinders and at their junctions are joints
What are the advantages to having jointed appendages?
act as hinges, allowing them to bend and extend its limbs
efficient movement by creating greater flexibility and range of movement
WHat are arthropod respiratory specializations?
metabolize more efficiently = move more effectively
large surface are of respiratory organs
How do arthopods obtain oxygen?
gills (crabs and lobsters etc.)
trachea (insects)
book lungs - stack of alternating air pockets between tissue (spiders)
What are features of the Subphylum Chelicerata?
no antenna body 2 tagmata (fused segments) = cephalothorax and abdomen
six pairs of appendages; first are modified feeding structures - chelicerae, second - pedipalps
What are Merostomata?
class of chelicerate arthropods like horseshoe crabs
What is tje oldest known horeshoe crab?
Lunataspis aurora - 445mya
When do horseshoe crabs mate?
each spring during the high tides of the new and full moons
Why do horseshoe crabs have blue blood?
they have oxygen carrying protein hemocyanin which contains copper.
What can horseshoe crab blood be used for?
test the efficacy of drugs against bacteria - as blood will gel when in contact with bacterial endotoxins
What are Arachnids? and numbers?
Class of Chelicerate arthropods - Spiders 40,000, mites and ticks 45000, scorpions, whip scorpions, pseudoscorpions, harvestmen
What are Myriapods?
centipedes and milipides
What are features of All Myriapoda?
two tagmata - head and trunk - with paired appendages on trunk segments
head with single pair of antennae, mandibles and 2 pairs of maxillae
What are Chilopoda?
Centipedes
